The present invention relates to a playback technique for reading data from an optical disk or other recording medium and reproducing pictures and sound, and, more particularly, the invention relates to a playback technique that is capable of simultaneously playing back data reproduced from a recording medium and data downloaded via a network.
The use of a DVD or other similar recording medium makes it possible to distribute/sell motion pictures and other video content with ease. The user can play back such a recording medium using a reproducing device at a desired time. Not only video and audio data, but also sub-picture data and other additional data is recorded as a video content. The additional data is reproduced and displayed as needed together with the video and audio data.
Further, a technology disclosed, for instance, by Japanese Patent Laid-open No. Hei 7-30814 is capable of receiving an audio data transmission, to which multi-language sub-picture data is added, and of displaying a subtitle on a screen in a user-selected language.